Well, the ENVOY lets you reveal the top 5 cards from your deck. The player to your left discards one, and you put the rest into your hand.
The other is the BLACK MARKET , which gives you +2 coins and lets you reveal the top three cards from a "Black Market" deck and buy one. The "Black Market" deck is comprised of up to 15 individual, face-down cards from other decks not being used in the game.